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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Plant Polymer Research » Research » Publications at this Location » Publication #143103
Title: PROTEIN CONCENTRATES AND ISOLATES FROM SOYBEAN HULLS VIA ULTRAFILTRATION/DIAFILTRATION

Author
item Sessa, David

Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2002
Publication Date: 5/4/2003
Citation: SESSA, D.J. PROTEIN CONCENTRATES AND ISOLATES FROM SOYBEAN HULLS VIA ULTRAFILTRATION/DIAFILTRATION. AMERICAN OIL CHEMIST SOCIETY MEETING. 2003. Abstract p. 113.

Interpretive Summary:

Technical Abstract: A commercial source of cold-processed soybean hulls with a high protein content of 26.4% was used to investigate processing methodologies to generate protein concentrates and isolates. Proteins were redistributed by selective sieving through a sieve series including a final #20 sieve to yield a fines fraction with 35.6% protein. The fines fraction was defatted. The resulting solids were aqueous extracted using a Ross HSM-100LC mixer-emulsifier equipped with a disintegrator head. Extracts were clarified by centrifugation and filtration. The protein dispersions were subjected to ultrafiltration/discontinuous diafiltration with a Pall Centramate tangential-flow system with a 5 kDa molecular weight cut-off polyether sulfane membrane. Freeze-dried retentates yielded a protein concentrate (>70% protein). The protein concentrates, enzymatically treated with commercial hemicellulase, were then diafiltered. This retentate, freeze-dried, was a protein isolate (90% protein). Sodium dodecylsulfate polyacrylamide gel electropheresis protein profiles verified the composition of those concentrates and isolates as resulting from cotyledenous components comprising a similar composition to aqueous extracts of defatted, dehulled soy flour with its complex array of proteins including Kunite trypsin inhibitor and 7S and 11S storage proteins. The combination of selective sieving to redistribute the proteins into a fines fraction, defatting, homogenization, ultrafiltration/diafiltration followed by hemicellulase break-down of soluble carbohydrates and further diafiltration proved successful for generating protein isolates from a predominantly cellulose matrix.